diff --git a/clang-tools-extra/clangd/ClangdLSPServer.cpp b/clang-tools-extra/clangd/ClangdLSPServer.cpp
--- a/clang-tools-extra/clangd/ClangdLSPServer.cpp
+++ b/clang-tools-extra/clangd/ClangdLSPServer.cpp
@@ -646,9 +646,7 @@
     const DidOpenTextDocumentParams &Params) {
   PathRef File = Params.textDocument.uri.file();
 
-  const std::string &Contents = Params.textDocument.text;
-
-  Server->addDocument(File, Contents,
+  Server->addDocument(File, Params.textDocument.text,
                       encodeVersion(Params.textDocument.version),
                       WantDiagnostics::Yes);
 }
@@ -677,8 +675,9 @@
       return;
     }
   }
-  Server->addDocument(File, NewCode, encodeVersion(Params.textDocument.version),
-                      WantDiags, Params.forceRebuild);
+  Server->addDocument(File, std::move(NewCode),
+                      encodeVersion(Params.textDocument.version), WantDiags,
+                      Params.forceRebuild);
 }
 
 void ClangdLSPServer::onDocumentDidSave(
diff --git a/clang-tools-extra/clangd/ClangdServer.cpp b/clang-tools-extra/clangd/ClangdServer.cpp
--- a/clang-tools-extra/clangd/ClangdServer.cpp
+++ b/clang-tools-extra/clangd/ClangdServer.cpp
@@ -211,16 +211,17 @@
   }
 }
 
-void ClangdServer::addDocument(PathRef File, llvm::StringRef Contents,
+void ClangdServer::addDocument(PathRef File, StringRef Contents,
                                llvm::StringRef Version,
                                WantDiagnostics WantDiags, bool ForceRebuild) {
-  std::string ActualVersion = DraftMgr.addDraft(File, Version, Contents);
+  auto RefContents = std::make_shared<std::string>(Contents);
+  std::string ActualVersion = DraftMgr.addDraft(File, Version, RefContents);
   ParseOptions Opts;
 
   // Compile command is set asynchronously during update, as it can be slow.
   ParseInputs Inputs;
   Inputs.TFS = &TFS;
-  Inputs.Contents = std::string(Contents);
+  Inputs.Contents = std::move(RefContents);
   Inputs.Version = std::move(ActualVersion);
   Inputs.ForceRebuild = ForceRebuild;
   Inputs.Opts = std::move(Opts);
@@ -358,7 +359,7 @@
         SpecFuzzyFind->CachedReq = CachedCompletionFuzzyFindRequestByFile[File];
       }
     }
-    ParseInputs ParseInput{IP->Command, &TFS, IP->Contents.str()};
+    ParseInputs ParseInput{IP->Command, &TFS, IP->Contents};
     ParseInput.Index = Index;
 
     CodeCompleteOpts.MainFileSignals = IP->Signals;
@@ -403,7 +404,7 @@
     if (!PreambleData)
       return CB(error("Failed to parse includes"));
 
-    ParseInputs ParseInput{IP->Command, &TFS, IP->Contents.str()};
+    ParseInputs ParseInput{IP->Command, &TFS, IP->Contents};
     ParseInput.Index = Index;
     CB(clangd::signatureHelp(File, Pos, *PreambleData, ParseInput));
   };
@@ -522,7 +523,7 @@
       return CB(R.takeError());
 
     if (Opts.WantFormat) {
-      auto Style = getFormatStyleForFile(File, InpAST->Inputs.Contents,
+      auto Style = getFormatStyleForFile(File, *InpAST->Inputs.Contents,
                                          *InpAST->Inputs.TFS);
       llvm::Error Err = llvm::Error::success();
       for (auto &E : R->GlobalChanges)
@@ -542,10 +543,10 @@
 // vector of pointers because GCC doesn't like non-copyable Selection.
 static llvm::Expected<std::vector<std::unique_ptr<Tweak::Selection>>>
 tweakSelection(const Range &Sel, const InputsAndAST &AST) {
-  auto Begin = positionToOffset(AST.Inputs.Contents, Sel.start);
+  auto Begin = positionToOffset(*AST.Inputs.Contents, Sel.start);
   if (!Begin)
     return Begin.takeError();
-  auto End = positionToOffset(AST.Inputs.Contents, Sel.end);
+  auto End = positionToOffset(*AST.Inputs.Contents, Sel.end);
   if (!End)
     return End.takeError();
   std::vector<std::unique_ptr<Tweak::Selection>> Result;
@@ -693,7 +694,7 @@
     if (!InpAST)
       return CB(InpAST.takeError());
     format::FormatStyle Style = getFormatStyleForFile(
-        File, InpAST->Inputs.Contents, *InpAST->Inputs.TFS);
+        File, *InpAST->Inputs.Contents, *InpAST->Inputs.TFS);
     CB(clangd::getHover(InpAST->AST, Pos, std::move(Style), Index));
   };
 
@@ -871,11 +872,11 @@
         if (!Inputs)
           return CB(Inputs.takeError());
         unsigned Start, End;
-        if (auto Offset = positionToOffset(Inputs->Inputs.Contents, R.start))
+        if (auto Offset = positionToOffset(*Inputs->Inputs.Contents, R.start))
           Start = *Offset;
         else
           return CB(Offset.takeError());
-        if (auto Offset = positionToOffset(Inputs->Inputs.Contents, R.end))
+        if (auto Offset = positionToOffset(*Inputs->Inputs.Contents, R.end))
           End = *Offset;
         else
           return CB(Offset.takeError());
diff --git a/clang-tools-extra/clangd/CodeComplete.cpp b/clang-tools-extra/clangd/CodeComplete.cpp
--- a/clang-tools-extra/clangd/CodeComplete.cpp
+++ b/clang-tools-extra/clangd/CodeComplete.cpp
@@ -1142,10 +1142,10 @@
   FrontendOpts.CodeCompletionAt.FileName = std::string(Input.FileName);
   std::tie(FrontendOpts.CodeCompletionAt.Line,
            FrontendOpts.CodeCompletionAt.Column) =
-      offsetToClangLineColumn(Input.ParseInput.Contents, Input.Offset);
+      offsetToClangLineColumn(*Input.ParseInput.Contents, Input.Offset);
 
   std::unique_ptr<llvm::MemoryBuffer> ContentsBuffer =
-      llvm::MemoryBuffer::getMemBuffer(Input.ParseInput.Contents,
+      llvm::MemoryBuffer::getMemBuffer(*Input.ParseInput.Contents,
                                        Input.FileName);
   // The diagnostic options must be set before creating a CompilerInstance.
   CI->getDiagnosticOpts().IgnoreWarnings = true;
@@ -1323,9 +1323,9 @@
 
   CodeCompleteResult run(const SemaCompleteInput &SemaCCInput) && {
     trace::Span Tracer("CodeCompleteFlow");
-    HeuristicPrefix = guessCompletionPrefix(SemaCCInput.ParseInput.Contents,
+    HeuristicPrefix = guessCompletionPrefix(*SemaCCInput.ParseInput.Contents,
                                             SemaCCInput.Offset);
-    populateContextWords(SemaCCInput.ParseInput.Contents);
+    populateContextWords(*SemaCCInput.ParseInput.Contents);
     if (Opts.Index && SpecFuzzyFind && SpecFuzzyFind->CachedReq.hasValue()) {
       assert(!SpecFuzzyFind->Result.valid());
       SpecReq = speculativeFuzzyFindRequestForCompletion(
@@ -1342,7 +1342,7 @@
       CCContextKind = Recorder->CCContext.getKind();
       IsUsingDeclaration = Recorder->CCContext.isUsingDeclaration();
       auto Style = getFormatStyleForFile(SemaCCInput.FileName,
-                                         SemaCCInput.ParseInput.Contents,
+                                         *SemaCCInput.ParseInput.Contents,
                                          *SemaCCInput.ParseInput.TFS);
       const auto NextToken = Lexer::findNextToken(
           Recorder->CCSema->getPreprocessor().getCodeCompletionLoc(),
@@ -1352,7 +1352,7 @@
       // If preprocessor was run, inclusions from preprocessor callback should
       // already be added to Includes.
       Inserter.emplace(
-          SemaCCInput.FileName, SemaCCInput.ParseInput.Contents, Style,
+          SemaCCInput.FileName, *SemaCCInput.ParseInput.Contents, Style,
           SemaCCInput.ParseInput.CompileCommand.Directory,
           &Recorder->CCSema->getPreprocessor().getHeaderSearchInfo());
       for (const auto &Inc : Includes.MainFileIncludes)
@@ -1848,7 +1848,7 @@
                                 const ParseInputs &ParseInput,
                                 CodeCompleteOptions Opts,
                                 SpeculativeFuzzyFind *SpecFuzzyFind) {
-  auto Offset = positionToOffset(ParseInput.Contents, Pos);
+  auto Offset = positionToOffset(*ParseInput.Contents, Pos);
   if (!Offset) {
     elog("Code completion position was invalid {0}", Offset.takeError());
     return CodeCompleteResult();
@@ -1857,7 +1857,7 @@
       FileName, Preamble ? Preamble->Includes : IncludeStructure(),
       SpecFuzzyFind, Opts);
   return (!Preamble || Opts.RunParser == CodeCompleteOptions::NeverParse)
-             ? std::move(Flow).runWithoutSema(ParseInput.Contents, *Offset,
+             ? std::move(Flow).runWithoutSema(*ParseInput.Contents, *Offset,
                                               *ParseInput.TFS)
              : std::move(Flow).run({FileName, *Offset, *Preamble,
                                     // We want to serve code completions with
@@ -1868,7 +1868,7 @@
 SignatureHelp signatureHelp(PathRef FileName, Position Pos,
                             const PreambleData &Preamble,
                             const ParseInputs &ParseInput) {
-  auto Offset = positionToOffset(ParseInput.Contents, Pos);
+  auto Offset = positionToOffset(*ParseInput.Contents, Pos);
   if (!Offset) {
     elog("Signature help position was invalid {0}", Offset.takeError());
     return SignatureHelp();
diff --git a/clang-tools-extra/clangd/Compiler.h b/clang-tools-extra/clangd/Compiler.h
--- a/clang-tools-extra/clangd/Compiler.h
+++ b/clang-tools-extra/clangd/Compiler.h
@@ -44,7 +44,7 @@
 struct ParseInputs {
   tooling::CompileCommand CompileCommand;
   const ThreadsafeFS *TFS;
-  std::string Contents;
+  std::shared_ptr<const std::string> Contents;
   // Version identifier for Contents, provided by the client and opaque to us.
   std::string Version = "null";
   // Prevent reuse of the cached preamble/AST. Slow! Useful to workaround
diff --git a/clang-tools-extra/clangd/DraftStore.h b/clang-tools-extra/clangd/DraftStore.h
--- a/clang-tools-extra/clangd/DraftStore.h
+++ b/clang-tools-extra/clangd/DraftStore.h
@@ -13,6 +13,7 @@
 #include "support/Path.h"
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include <mutex>
 #include <string>
@@ -21,6 +22,10 @@
 namespace clang {
 namespace clangd {
 
+std::unique_ptr<llvm::MemoryBuffer>
+getSharedStringBuffer(std::shared_ptr<const std::string> Contents,
+                      StringRef BufferName = "");
+
 /// A thread-safe container for files opened in a workspace, addressed by
 /// filenames. The contents are owned by the DraftStore.
 /// Each time a draft is updated, it is assigned a version. This can be
@@ -43,7 +48,7 @@
   /// If version is empty, one will be automatically assigned.
   /// Returns the version.
   std::string addDraft(PathRef File, llvm::StringRef Version,
-                       StringRef Contents);
+                       std::shared_ptr<const std::string> Contents);
 
   /// Remove the draft from the store.
   void removeDraft(PathRef File);
diff --git a/clang-tools-extra/clangd/DraftStore.cpp b/clang-tools-extra/clangd/DraftStore.cpp
--- a/clang-tools-extra/clangd/DraftStore.cpp
+++ b/clang-tools-extra/clangd/DraftStore.cpp
@@ -74,13 +74,13 @@
 }
 
 std::string DraftStore::addDraft(PathRef File, llvm::StringRef Version,
-                                 llvm::StringRef Contents) {
+                                 std::shared_ptr<const std::string> Contents) {
   std::lock_guard<std::mutex> Lock(Mutex);
 
   auto &D = Drafts[File];
   updateVersion(D.D, Version);
   std::time(&D.MTime);
-  D.D.Contents = std::make_shared<std::string>(Contents);
+  D.D.Contents = std::move(Contents);
   return D.D.Version;
 }
 
@@ -119,10 +119,16 @@
   auto MemFS = llvm::makeIntrusiveRefCnt<llvm::vfs::InMemoryFileSystem>();
   std::lock_guard<std::mutex> Guard(Mutex);
   for (const auto &Draft : Drafts)
-    MemFS->addFile(Draft.getKey(), Draft.getValue().MTime,
-                   std::make_unique<SharedStringBuffer>(
-                       Draft.getValue().D.Contents, Draft.getKey()));
+    MemFS->addFile(
+        Draft.getKey(), Draft.getValue().MTime,
+        getSharedStringBuffer(Draft.getValue().D.Contents, Draft.getKey()));
   return MemFS;
 }
+std::unique_ptr<llvm::MemoryBuffer>
+getSharedStringBuffer(std::shared_ptr<const std::string> Contents,
+                      StringRef BufferName) {
+  return std::make_unique<SharedStringBuffer>(std::move(Contents), BufferName);
+}
+
 } // namespace clangd
 } // namespace clang
diff --git a/clang-tools-extra/clangd/ParsedAST.cpp b/clang-tools-extra/clangd/ParsedAST.cpp
--- a/clang-tools-extra/clangd/ParsedAST.cpp
+++ b/clang-tools-extra/clangd/ParsedAST.cpp
@@ -14,6 +14,7 @@
 #include "Compiler.h"
 #include "Config.h"
 #include "Diagnostics.h"
+#include "DraftStore.h"
 #include "Headers.h"
 #include "IncludeFixer.h"
 #include "Preamble.h"
@@ -270,8 +271,7 @@
   }
   auto Clang = prepareCompilerInstance(
       std::move(CI), PreamblePCH,
-      llvm::MemoryBuffer::getMemBufferCopy(Inputs.Contents, Filename), VFS,
-      ASTDiags);
+      getSharedStringBuffer(Inputs.Contents, Filename), VFS, ASTDiags);
   if (!Clang)
     return None;
 
@@ -359,9 +359,9 @@
   llvm::Optional<IncludeFixer> FixIncludes;
   auto BuildDir = VFS->getCurrentWorkingDirectory();
   if (Inputs.Index && !BuildDir.getError()) {
-    auto Style = getFormatStyleForFile(Filename, Inputs.Contents, *Inputs.TFS);
+    auto Style = getFormatStyleForFile(Filename, *Inputs.Contents, *Inputs.TFS);
     auto Inserter = std::make_shared<IncludeInserter>(
-        Filename, Inputs.Contents, Style, BuildDir.get(),
+        Filename, *Inputs.Contents, Style, BuildDir.get(),
         &Clang->getPreprocessor().getHeaderSearchInfo());
     if (Preamble) {
       for (const auto &Inc : Preamble->Includes.MainFileIncludes)
diff --git a/clang-tools-extra/clangd/Preamble.cpp b/clang-tools-extra/clangd/Preamble.cpp
--- a/clang-tools-extra/clangd/Preamble.cpp
+++ b/clang-tools-extra/clangd/Preamble.cpp
@@ -237,7 +237,6 @@
   EmptyFS FS;
   // Build and run Preprocessor over the preamble.
   ParseInputs PI;
-  PI.Contents = Contents.str();
   PI.TFS = &FS;
   PI.CompileCommand = Cmd;
   IgnoringDiagConsumer IgnoreDiags;
@@ -320,7 +319,7 @@
   // Note that we don't need to copy the input contents, preamble can live
   // without those.
   auto ContentsBuffer =
-      llvm::MemoryBuffer::getMemBuffer(Inputs.Contents, FileName);
+      llvm::MemoryBuffer::getMemBuffer(*Inputs.Contents, FileName);
   auto Bounds = ComputePreambleBounds(*CI.getLangOpts(), *ContentsBuffer, 0);
 
   trace::Span Tracer("BuildPreamble");
@@ -373,7 +372,7 @@
                           const ParseInputs &Inputs, PathRef FileName,
                           const CompilerInvocation &CI) {
   auto ContentsBuffer =
-      llvm::MemoryBuffer::getMemBuffer(Inputs.Contents, FileName);
+      llvm::MemoryBuffer::getMemBuffer(*Inputs.Contents, FileName);
   auto Bounds = ComputePreambleBounds(*CI.getLangOpts(), *ContentsBuffer, 0);
   auto VFS = Inputs.TFS->view(Inputs.CompileCommand.Directory);
   return compileCommandsAreEqual(Inputs.CompileCommand,
@@ -417,7 +416,7 @@
          BaselineScan.takeError());
     return PreamblePatch::unmodified(Baseline);
   }
-  auto ModifiedScan = scanPreamble(Modified.Contents, Modified.CompileCommand);
+  auto ModifiedScan = scanPreamble(*Modified.Contents, Modified.CompileCommand);
   if (!ModifiedScan) {
     elog("Failed to scan modified contents of {0}: {1}", FileName,
          ModifiedScan.takeError());
@@ -470,7 +469,8 @@
       }
       // Include is new in the modified preamble. Inject it into the patch and
       // use #line to set the presumed location to where it is spelled.
-      auto LineCol = offsetToClangLineColumn(Modified.Contents, Inc.HashOffset);
+      auto LineCol =
+          offsetToClangLineColumn(*Modified.Contents, Inc.HashOffset);
       Patch << llvm::formatv("#line {0}\n", LineCol.first);
       Patch << llvm::formatv(
           "#{0} {1}\n", spellingForIncDirective(Inc.Directive), Inc.Written);
diff --git a/clang-tools-extra/clangd/TUScheduler.h b/clang-tools-extra/clangd/TUScheduler.h
--- a/clang-tools-extra/clangd/TUScheduler.h
+++ b/clang-tools-extra/clangd/TUScheduler.h
@@ -40,7 +40,7 @@
 };
 
 struct InputsAndPreamble {
-  llvm::StringRef Contents;
+  std::shared_ptr<const std::string> Contents;
   const tooling::CompileCommand &Command;
   // This can be nullptr if no preamble is available.
   const PreambleData *Preamble;
diff --git a/clang-tools-extra/clangd/TUScheduler.cpp b/clang-tools-extra/clangd/TUScheduler.cpp
--- a/clang-tools-extra/clangd/TUScheduler.cpp
+++ b/clang-tools-extra/clangd/TUScheduler.cpp
@@ -753,6 +753,14 @@
 #endif
 }
 
+static bool areInputsSame(const ParseInputs &L, const ParseInputs &R) {
+  if (L.CompileCommand != R.CompileCommand)
+    return false;
+  StringRef LContents = L.Contents ? StringRef(*L.Contents) : "";
+  StringRef RContents = R.Contents ? StringRef(*R.Contents) : "";
+  return LContents == RContents;
+}
+
 void ASTWorker::update(ParseInputs Inputs, WantDiagnostics WantDiags,
                        bool ContentChanged) {
   std::string TaskName = llvm::formatv("Update ({0})", Inputs.Version);
@@ -783,9 +791,7 @@
     else
       Inputs.CompileCommand = CDB.getFallbackCommand(FileName);
 
-    bool InputsAreTheSame =
-        std::tie(FileInputs.CompileCommand, FileInputs.Contents) ==
-        std::tie(Inputs.CompileCommand, Inputs.Contents);
+    bool InputsAreTheSame = areInputsSame(FileInputs, Inputs);
     // Cached AST is invalidated.
     if (!InputsAreTheSame) {
       IdleASTs.take(this);
@@ -1015,9 +1021,7 @@
       return;
   }
   // Used to check whether we can update AST cache.
-  bool InputsAreLatest =
-      std::tie(FileInputs.CompileCommand, FileInputs.Contents) ==
-      std::tie(Inputs.CompileCommand, Inputs.Contents);
+  bool InputsAreLatest = areInputsSame(FileInputs, Inputs);
   // Take a shortcut and don't report the diagnostics, since they should be the
   // same. All the clients should handle the lack of OnUpdated() call anyway to
   // handle empty result from buildAST.
@@ -1439,7 +1443,7 @@
 
 struct TUScheduler::FileData {
   /// Latest inputs, passed to TUScheduler::update().
-  std::string Contents;
+  std::shared_ptr<const std::string> Contents;
   ASTWorkerHandle Worker;
 };
 
@@ -1500,7 +1504,7 @@
     FD = std::unique_ptr<FileData>(
         new FileData{Inputs.Contents, std::move(Worker)});
     ContentChanged = true;
-  } else if (FD->Contents != Inputs.Contents) {
+  } else if (*FD->Contents != *Inputs.Contents) {
     ContentChanged = true;
     FD->Contents = Inputs.Contents;
   }
diff --git a/clang-tools-extra/clangd/tool/Check.cpp b/clang-tools-extra/clangd/tool/Check.cpp
--- a/clang-tools-extra/clangd/tool/Check.cpp
+++ b/clang-tools-extra/clangd/tool/Check.cpp
@@ -125,11 +125,12 @@
     Inputs.TFS = &TFS;
     Inputs.ClangTidyProvider = Opts.ClangTidyProvider;
     if (Contents.hasValue()) {
-      Inputs.Contents = *Contents;
-      log("Imaginary source file contents:\n{0}", Inputs.Contents);
+      Inputs.Contents = std::make_shared<std::string>(*Contents);
+      log("Imaginary source file contents:\n{0}", *Inputs.Contents);
     } else {
       if (auto Contents = TFS.view(llvm::None)->getBufferForFile(File)) {
-        Inputs.Contents = Contents->get()->getBuffer().str();
+        Inputs.Contents =
+            std::make_shared<std::string>(Contents->get()->getBuffer());
       } else {
         elog("Couldn't read {0}: {1}", File, Contents.getError().message());
         return false;
@@ -148,7 +149,7 @@
 
     // FIXME: Check that resource-dir/built-in-headers exist?
 
-    Style = getFormatStyleForFile(File, Inputs.Contents, TFS);
+    Style = getFormatStyleForFile(File, *Inputs.Contents, TFS);
 
     return true;
   }
@@ -197,7 +198,7 @@
     for (const auto &Tok : SpelledTokens) {
       unsigned Start = AST->getSourceManager().getFileOffset(Tok.location());
       unsigned End = Start + Tok.length();
-      Position Pos = offsetToPosition(Inputs.Contents, Start);
+      Position Pos = offsetToPosition(*Inputs.Contents, Start);
       // FIXME: dumping the tokens may leak sensitive code into bug reports.
       // Add an option to turn this off, once we decide how options work.
       vlog("  {0} {1}", Pos, Tok.text(AST->getSourceManager()));
diff --git a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
--- a/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
+++ b/clang-tools-extra/clangd/unittests/CodeCompleteTests.cpp
@@ -153,7 +153,8 @@
 
   MockFS FS;
   Annotations Test(Text);
-  ParseInputs ParseInput{tooling::CompileCommand(), &FS, Test.code().str()};
+  ParseInputs ParseInput{tooling::CompileCommand(), &FS,
+                         std::make_shared<std::string>(Test.code())};
   return codeComplete(FilePath, Test.point(), /*Preamble=*/nullptr, ParseInput,
                       Opts);
 }
diff --git a/clang-tools-extra/clangd/unittests/DraftStoreTests.cpp b/clang-tools-extra/clangd/unittests/DraftStoreTests.cpp
--- a/clang-tools-extra/clangd/unittests/DraftStoreTests.cpp
+++ b/clang-tools-extra/clangd/unittests/DraftStoreTests.cpp
@@ -22,20 +22,21 @@
   DraftStore DS;
   Path File = "foo.cpp";
 
-  EXPECT_EQ("25", DS.addDraft(File, "25", ""));
+  EXPECT_EQ("25", DS.addDraft(File, "25", std::make_shared<std::string>("")));
   EXPECT_EQ("25", DS.getDraft(File)->Version);
   EXPECT_EQ("", *DS.getDraft(File)->Contents);
 
-  EXPECT_EQ("26", DS.addDraft(File, "", "x"));
+  EXPECT_EQ("26", DS.addDraft(File, "", std::make_shared<std::string>("x")));
   EXPECT_EQ("26", DS.getDraft(File)->Version);
   EXPECT_EQ("x", *DS.getDraft(File)->Contents);
 
-  EXPECT_EQ("27", DS.addDraft(File, "", "x")) << "no-op change";
+  EXPECT_EQ("27", DS.addDraft(File, "", std::make_shared<std::string>("x")))
+      << "no-op change";
   EXPECT_EQ("27", DS.getDraft(File)->Version);
   EXPECT_EQ("x", *DS.getDraft(File)->Contents);
 
   // We allow versions to go backwards.
-  EXPECT_EQ("7", DS.addDraft(File, "7", "y"));
+  EXPECT_EQ("7", DS.addDraft(File, "7", std::make_shared<std::string>("y")));
   EXPECT_EQ("7", DS.getDraft(File)->Version);
   EXPECT_EQ("y", *DS.getDraft(File)->Contents);
 }
diff --git a/clang-tools-extra/clangd/unittests/FileIndexTests.cpp b/clang-tools-extra/clangd/unittests/FileIndexTests.cpp
--- a/clang-tools-extra/clangd/unittests/FileIndexTests.cpp
+++ b/clang-tools-extra/clangd/unittests/FileIndexTests.cpp
@@ -295,12 +295,12 @@
   )cpp";
   PI.TFS = &FS;
 
-  PI.Contents = R"cpp(
+  PI.Contents = std::make_shared<std::string>(R"cpp(
     #include "foo.h"
     namespace ns_in_source {
       int func_in_source();
     }
-  )cpp";
+  )cpp");
 
   // Rebuild the file.
   IgnoreDiagnostics IgnoreDiags;
diff --git a/clang-tools-extra/clangd/unittests/TUSchedulerTests.cpp b/clang-tools-extra/clangd/unittests/TUSchedulerTests.cpp
--- a/clang-tools-extra/clangd/unittests/TUSchedulerTests.cpp
+++ b/clang-tools-extra/clangd/unittests/TUSchedulerTests.cpp
@@ -93,7 +93,7 @@
     ParseInputs Inputs;
     Inputs.CompileCommand = *CDB.getCompileCommand(File);
     Inputs.TFS = &FS;
-    Inputs.Contents = std::move(Contents);
+    Inputs.Contents = std::make_shared<std::string>(std::move(Contents));
     Inputs.Opts = ParseOptions();
     return Inputs;
   }
@@ -528,7 +528,7 @@
                 EXPECT_EQ(File, boundPath());
 
                 ASSERT_TRUE((bool)AST);
-                EXPECT_EQ(AST->Inputs.Contents, Inputs.Contents);
+                EXPECT_EQ(*AST->Inputs.Contents, *Inputs.Contents);
                 EXPECT_EQ(AST->Inputs.Version, Inputs.Version);
                 EXPECT_EQ(AST->AST.version(), Inputs.Version);
 
@@ -548,7 +548,7 @@
                 EXPECT_EQ(File, boundPath());
 
                 ASSERT_TRUE((bool)Preamble);
-                EXPECT_EQ(Preamble->Contents, Inputs.Contents);
+                EXPECT_EQ(*Preamble->Contents, *Inputs.Contents);
 
                 std::lock_guard<std::mutex> Lock(Mut);
                 ++TotalPreambleReads;
diff --git a/clang-tools-extra/clangd/unittests/TestTU.cpp b/clang-tools-extra/clangd/unittests/TestTU.cpp
--- a/clang-tools-extra/clangd/unittests/TestTU.cpp
+++ b/clang-tools-extra/clangd/unittests/TestTU.cpp
@@ -54,7 +54,7 @@
   Argv.push_back(FullFilename);
   Inputs.CompileCommand.Filename = FullFilename;
   Inputs.CompileCommand.Directory = testRoot();
-  Inputs.Contents = Code;
+  Inputs.Contents = std::make_shared<std::string>(Code);
   if (OverlayRealFileSystemForModules)
     FS.OverlayRealFileSystemForModules = true;
   Inputs.TFS = &FS;